/*
 * Copyright (c) 2007, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.grizzly.http.util;

import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;

/**
 * An internationalization / localization helper class which reduces the bother of handling ResourceBundles and takes
 * care of the common cases of message formatting which otherwise require the creation of Object arrays and such.
 * <p/>
 * <p>
 * The StringManager operates on a package basis. One StringManager per package can be created and accessed via the
 * getManager method call.
 * <p/>
 * <p>
 * The StringManager will look for a ResourceBundle named by the package name given plus the suffix of "LocalStrings".
 * In practice, this means that the localized information will be contained in a LocalStrings.properties file located in
 * the package directory of the classpath.
 * <p/>
 * <p>
 * Please see the documentation for java.util.ResourceBundle for more information.
 *
 * @author James Duncan Davidson [duncan@eng.sun.com]
 * @author James Todd [gonzo@eng.sun.com]
 * @author Mel Martinez [mmartinez@g1440.com]
 * @version $Revision: 1.2 $ $Date: 2005/12/08 01:29:37 $
 * @see java.util.ResourceBundle
 */

public class StringManager {

    /**
     * The ResourceBundle for this StringManager.
     */

    private ResourceBundle bundle;

    /**
     * Creates a new StringManager for a given package. This is a private method and all access to it is arbitrated by the
     * static getManager method call so that only one StringManager per package will be created.
     *
     * @param packageName Name of package to create StringManager for.
     */

    private StringManager(String packageName, ClassLoader loader) {
        this(packageName, Locale.getDefault(), loader);
    }

    private StringManager(String packageName, Locale loc, ClassLoader loader) {
        String bundleName = packageName + ".LocalStrings";
        try {
            bundle = ResourceBundle.getBundle(bundleName, loc, loader);
        } catch (MissingResourceException ex) {
            bundle = ResourceBundle.getBundle(bundleName, Locale.US, loader);
        }
    }

    private StringManager(ResourceBundle bundle) {
        this.bundle = bundle;
    }

    /**
     * Get a string from the underlying resource bundle or return null if the String is not found.
     *
     * @param key to desired resource String
     * @return resource String matching <i>key</i> from underlying bundle or null if not found.
     * @throws IllegalArgumentException if <i>key</i> is null.
     */

    public String getString(String key) {
        if (key == null) {
            String msg = "key may not have a null value";

            throw new IllegalArgumentException(msg);
        }

        String str;

        try {
            str = bundle.getString(key);
        } catch (MissingResourceException mre) {
            // bad: shouldn't mask an exception the following way:
            // str = "[cannot find message associated with key '" + key + "' due to " + mre + "]";
            // because it hides the fact that the String was missing
            // from the calling code.
            // good: could just throw the exception (or wrap it in another)
            // but that would probably cause much havoc on existing
            // code.
            // better: consistent with container pattern to
            // simply return null. Calling code can then do
            // a null check.
            str = null;
        }

        return str;
    }

    /**
     * Get a string from the underlying resource bundle and format it with the given set of arguments.
     *
     * @param key
     * @param args
     */

    public String getString(String key, Object[] args) {
        String iString;
        String value = getString(key);

        // this check for the runtime exception is some pre 1.1.6
        // VM's don't do an automatic toString() on the passed in
        // objects and barf out

        try {
            // ensure the arguments are not null so pre 1.2 VM's don't barf
            if (args == null) {
                args = new Object[1];
            }

            Object[] nonNullArgs = args;
            for (int i = 0; i < args.length; i++) {
                if (args[i] == null) {
                    if (nonNullArgs == args) {
                        nonNullArgs = args.clone();
                    }
                    nonNullArgs[i] = "null";
                }
            }
            if (value == null) {
                value = key;
            }
            iString = MessageFormat.format(value, nonNullArgs);
        } catch (IllegalArgumentException iae) {
            StringBuilder buf = new StringBuilder();
            buf.append(value);
            for (int i = 0; i < args.length; i++) {
                buf.append(" arg[").append(i).append("]=").append(args[i]);
            }
            iString = buf.toString();
        }
        return iString;
    }

    /**
     * Get a string from the underlying resource bundle and format it with the given object argument. This argument can of
     * course be a String object.
     *
     * @param key
     * @param arg
     */

    public String getString(String key, Object arg) {
        Object[] args = new Object[] { arg };
        return getString(key, args);
    }

    /**
     * Get a string from the underlying resource bundle and format it with the given object arguments. These arguments can
     * of course be String objects.
     *
     * @param key
     * @param arg1
     * @param arg2
     */

    public String getString(String key, Object arg1, Object arg2) {
        Object[] args = new Object[] { arg1, arg2 };
        return getString(key, args);
    }

    /**
     * Get a string from the underlying resource bundle and format it with the given object arguments. These arguments can
     * of course be String objects.
     *
     * @param key
     * @param arg1
     * @param arg2
     * @param arg3
     */

    public String getString(String key, Object arg1, Object arg2, Object arg3) {
        Object[] args = new Object[] { arg1, arg2, arg3 };
        return getString(key, args);
    }

    /**
     * Get a string from the underlying resource bundle and format it with the given object arguments. These arguments can
     * of course be String objects.
     *
     * @param key
     * @param arg1
     * @param arg2
     * @param arg3
     * @param arg4
     */

    public String getString(String key, Object arg1, Object arg2, Object arg3, Object arg4) {
        Object[] args = new Object[] { arg1, arg2, arg3, arg4 };
        return getString(key, args);
    }
    // --------------------------------------------------------------
    // STATIC SUPPORT METHODS
    // --------------------------------------------------------------

    private static final Map<String, StringManager> managers = new HashMap<>();

    /**
     * Get the StringManager for a particular package. If a manager for a package already exists, it will be reused, else a
     * new StringManager will be created and returned.
     *
     * @param packageName
     */

    public synchronized static StringManager getManager(String packageName, ClassLoader loader) {
        StringManager mgr = managers.get(packageName);
        if (mgr == null) {
            mgr = new StringManager(packageName, loader);
            managers.put(packageName, mgr);
        }
        return mgr;
    }

    /**
     * Get the StringManager for a particular package. If a manager for a package already exists, it will be reused, else a
     * new StringManager will be created and returned.
     *
     * @param bundle
     */
    public synchronized static StringManager getManager(ResourceBundle bundle) {
        return new StringManager(bundle);
    }

    /**
     * Get the StringManager for a particular package and Locale. If a manager for a package already exists, it will be
     * reused, else a new StringManager will be created for that Locale and returned.
     *
     * @param packageName
     */

    public synchronized static StringManager getManager(String packageName, Locale loc, ClassLoader loader) {
        StringManager mgr = managers.get(packageName + '_' + loc.toString());
        if (mgr == null) {
            mgr = new StringManager(packageName, loc, loader);
            managers.put(packageName + '_' + loc.toString(), mgr);
        }
        return mgr;
    }

}
